Changing Workweek
We currently run our workweek from Tuesday to Monday. We would like to move to Sunday to Saturday. So we have 2 options. On the conversion payroll, we would shorten the payroll to 12 days. Or is it possible to lengthen the payroll to 19 days? Or is it possible to have a payroll that is only 5 days so to get us to the next Sunday? Also, how with these scenarios effect salaried employees?
Comments

Payrolls and workweeks are legally two very different things. Workweeks are always seven days long, used for MW/OT calculations, and always ignore the payroll period. They are intended to be fixed and unchanging. Under the extremely rare cases in which a workweek is changed, the calculations must be done both ways for the change over payroll and the employee must be paid the larger of the two calculations. And if you keep changing the workweek, then legally you are doing something wrong. Every employer I have ever worked for used a workweek ending Sunday midnight although we for different employers used BW or SM payrolls, with different definitions.

David has it right. It looks like you are paying biweeky. If you change the workweek, you do not have to change the pay dates. If you are changing the pay dates, that presents a different set of problems  that is, the employees will either get less pay than usual during the change over (12 days instead of 14 days) or will have to wait longer for the next check (19 days)  either way they are likely to be upset unless they have been prepared for the change. This is similar to a change in pay frequency (changing from biweekly to semimonthly, for example. In that case, the workweeks do not change, as David indicated.
A workweek change does not have to affect pay days, There will be the same time period involved in the pay days, However, when overtime pay is paid to employees may be affected.
Regulations 29 CFR 778.301 and 778.302 describe a method for handling overtime during a change in workweeks. This method does not have to be used, however the federal department of labor indicates that it will assume the overtime requirements are met if the specified method is used. If you use some other method, you have to be prepared to demonstrate the employees were sufficiently compensated for any overtime that was worked.
A change in the start of the workweek necessarily involves two workweeks. The old workweek is the 168hour period that starts at the old start time and the new workweek is the 168hour period that starts at the new start time.
The necessity for both workweeks during the change over to be 168 consecutive hours creates an overlap period where some of the hours in each workweek are also in the other. I'm going to assume both your current and proposed workweeks start at Midnight (12:00 a,m,), The current workweek starts 12:00 a.m. Tuesday and the new workweek will start 12:00 a.m. Sunday. The overlap period is 12:00 a.m. Sunday to 12:00 a.m, Tuesday. It can't be the other way around because then you would have a gap rather than an overlap.
In your case, the overlap period is Sunday and Monday and the 48 hours of those two days fall into both workweeks.
The easiest way to avoid a problem is to not have any employees work during the overlap period that is, On the Sunday and Monday of the change. However, this can also work if no employee works any overtime during either of the workweeks.For example, in your case, suppose Employee A regularly works 8 hours each day Monday through Friday. In "old" Tuesday though Monday workweek, A will have worked Tuesday though Friday and the following Monday for forty hours. In the "new" Sunday through Saturday workweek, A will have worked Monday Through Friday for forty hours. Note that the eight hours worked on Monday in the overlap period is in both workweeks. That is, A only worked 72 hours during the change over period.
Otherwise the method laid out in the regulations involves the following steps:
Count any hours worked during the overlap period as worked in the old workweek and not in the new work week. On this basis, compute straight time and overtime compensation due for each of the two workweeks and total the two sums.
Count any hours worked during the overlap period as worked in the new workweek and not in the old work week. On this basis, compute straight time and overtime compensation due for each of the two workweeks and total the two sums.
Pay the employee an amount that is not less than the greater of the amounts computed in steps 1 and 2.
Let's change the example and suppose employee A regularly works 8 hours each day Tuesday through Saturday. In "old" Tuesday though Monday workweek, but is switched to a Monday through Friday schedule in the "new" workweek.
A will have worked Tuesday though Saturday and the following Monday in the "old" workweek. That is, the eight hours worked on the overlap Monday are included in the "old" workweek under step 1. A will have worked 48 hours in the "old workweek and 32 hours in the new workweek. If A's regular rate is $10 per hour, Under step 1, A's total compensation for the changeover period is $720 in regular pay (72 hours worked) and an additional half time amount of $40 for eight hours of overtime for a total of $760.
Under step 2, The overlap Monday hours will be included in the "new" workweek, but not in the "old" workweek, for a total of 40 hours for each workweek. That is, Tuesday thought Saturday for the "old" workweek and Monday through Friday for the "new" workweek. Here A is due $720 in regular pay and there is no overtime premium.
A must be paid at least $760 for the changeover period for A's employer to be assumed to be in compliance.
The regulation also provides that where there is a nonstatutory obligation to pay more than the amount computed under this procedure, that obligation is not superseded by this procedure.